Over the last decade, MTHFR polymorphisms and elevated total plasma homocysteine concentrations have also been associated with a broad range of conditions in adulthood, albeit more modestly, e.g., with schizophrenia, unipolar depression, bipolar disorder [13-15], diabetic retinopathy[16], ovulatory infertility [17,18], cardiovascular disease, atherosclerosis, and thromboembolic events [19,20], renal failure [21], dementia, and cognitive impairment [22,23]. The gene discussed is MTHFR; the disease is schizophrenia.